Getting a Clear Picture - Individual Zone Testing of the Khuff Reservoir Through FirstApplication of a Zonal Isolation Completion and Nondamaging Drilling andCompletion Fluids

摘要

The North Field is a major gas field in the Khuff formation,rnoffshore Qatar. Traditionally, this reservoir has been drilledrnwith reduced solids drilling fluids and completed by heavilyrnacidising the payzone in order to maximize production.rnThe purpose of appraisal well NFS 1-1 was to obtain highqualityrnrepresentative formation fluid samples from each ofrnthe identified producing zones in the Khuff. The detailed gasrnanalysis was required to determine the specifications of thernGas-To-Liquid (GTL) Plant to be constructed to processrnproduction from the field.rnIn order to achieve this, a new testing technique wasrndeveloped using a ported liner, a high density, low solidsrnreservoir drilling fluid, and a combination enzyme/chelatingrnagent breaker to remove the filter cake prior to testing thernindividual zones. In order to ensure the success of thisrnchallenging operation, a high degree of collaboration betweenrnthe operator and the supplier of drilling, completion andrnstimulation fluids was imperative.rnThe design and engineering of the fluids used duringrncoring, logging, completion and well testing of NFS 1-1 isrnexamined in this paper.